The hepatitis E virus (HEV) causes self-limiting viral hepatitis. It is now global, both in developing and low-industrialized countries. With infection, the predominance of infections is asymptomatic but can cause death. Pregnant women are particularly vulnerable to severe complications. This article summarizes the current knowledge about HEV infection during pregnancy, focusing on immunology, transmission, complications in both pregnant and newborn women, and polymer-boosted vaccines. The development of a polymer-reinforced vaccine may in the future solve the problem of the HEV virus, which is particularly dangerous for pregnant women. HEV was the first to be officially named an epidemic of unexplained acute hepatitis in the early 80s. It leads to about 20 million infections and up to 70,000 deaths per year. Infection in the predominance of infections is asymptomatic but can reach mortality of up to 25% in pregnant women. HEV has 8 genotypes. Genotype 1 is found mainly in Asia and Africa and 2 is detected in Mexico and Africa, They are diagnosed only in humans. Genotypes 3 and 4 can infect both humans and animals worldwide, and in recent years there has been an increase in infections in Europe. All genotypes belong to one serotype. HEV is transmitted zoonotically through the consumption of infected undercooked meat or by the fecal-oral route through drinking contaminated water.